NASA Student Launch 2018 - 2019 Flight Readiness Review -- Presentation 1
Vehicle Design and Dimensions Diameter Recovery System (inches) (inches) Length Mass Final Motor Predicted Vehicle CG (in, CP (in, (inches) (lbs) Selection Altitude (feet) Material nose) nose Drogue Main Outer Inner Carbon 104.27 5.52 5.34 18.1 L1000 18 60 5280 59.873 78.878 Fiber 2
Key Design Features Carbon Fiber Airframe ● ○ Rolled in house ● Removable Fins As Built CP adjustment ○ ● ADAS (ADaptive Aerobraking System) Adaptive deployment of drag fins ○ ○ Guides vehicle to predetermined altitude via apogee reduction from drag ● Rover Payload Compact rover ○ ○ Object detection system Actuated Landing Correction ○ 3
Motor Characteristics Total Impulse: 2714.0Ns AeroTech L1000 Length x Diameter: 63.5cm x 54mm Weight (Wet, Dry, Prop): 2194g, 1400g, 794g This motor was chosen as it makes the vehicle overshoot the mile target by a suitable amount, allowing ADAS to work and bring the altitude to exactly one mile. 4
Vehicle Stability and Flight Characteristics CP 78.878” CG 59.873” Stability 2.28 cal margin Thrust to 9.8 weight ratio Rail exit 61 ft/s velocity 5
Mass Statement The figure to the right outlines the mass of the vehicle and its subparts. The vehicle weighs an additional 2194g due to the motor at ignition, and after motor burnout, weighs an additional 794g. 6
Parachute Sizes, Decent Rates and Kinetic Energy Parachute Diameter Decent Rate ● The tethered rocket must hit the (Predicted) ground at a velocity less than 6.42 m/s in order to meet NASA Drogue 18" 60.27 ft/s SLI recovery requirements. Main 60” 14.86 ft/s ● Simulations predict rocket will land at 6.04 m/s. 7
Winds Wind Speed Drift Drift (by The table to the right outlines the (OpenRocket) hand) drift of the vehicle from two 0 mph / 0 m/s 2.4m / 8 feet 0m / 0 feet methods, OpenRocket simulation and by hand. It should be noted that even 5 mph / 2.2 63.5m / 208 158.4m / under 20mph winds, the vehicle m/s feet 519.7 feet remains within the 2500ft limit. 10 mph / 4.47 129m / 423 321.84m / m/s feet 1056 feet 15 mph / 6.7 224.5m / 737 482.4m / 1581 m/s feet feet 20 mph / 8.9 320.5m / 1052 640.8m / 2101 m/s feet feet 8
Vehicle Demonstration Flight Results Failure Potential Solutions Parachute cords became tangled and the main Practice folding parachutes in order to prevent parachute was not able to deploy tangling in the future The shear pins holding the payload broke and the Larger, stronger shear pins that are able to resist payload was lost during decoupling forces of parachute deployment at apogee. Connecting wires for the ADAS came loose and the Solder wire connections in order to prevent fins were unable to deploy disconnection 9
Vehicle Demonstration Flight Results EasyMini (altimeter) data from full scale flight 1 10
Recovery Tests Recovery system tests: - Ground deployment test to verify black powder charge is sufficient. - Drop tests to verify parachute packing technique is effective 11
Requirements Verification Summary (Vehicle) The majority of the Vehicle requirements have either been completed or are in progress. The lack of total competition is partially due to the need to re-fly the full scale, and because some requirements are only completed at the competition. Despite this, steps are being taken to complete as many requirements as possible before the competition in April. 12
Payload Design and Dimensions ● Systems ○ Soil Collection (Bulldozer design) ○ Drive ○ ODAS (Object Detection and Avoidance) ○ ALC (Actuated Landing Correction) Dimensions ● Depth: 2.87 inches ○ ○ Width: 3.49 inches Length: 8.79 inches ○ ○ Weight: 13 oz Material: PLA ○ 13
Kay Design Features of Payload - Actuated Landing Correction - Forward bulldozer like scoop - Small form factor 14
Payload Integration Payload ALC system redesigned for stability and simplicity Ball bearing passive actuation Nose cone locking mechanism ● Support force split across large section ● Rotating coupler held in place through of airframe commutative attachment to airframe ● Securement through use of semi ● Utilizing stronger shear screws to permanent bolts withstand launch forces ● Redundant securement cable still in place, just secures nose cone so less force 15
Payload Demonstration Flight Results Payload bay and rover failed in several ● key ways: 1. Sled came unsecured 2. Rover came unsecured 3. Shear pins broke prematurely 4. Payload bay opened up mid air 5. Secondary retention system failed ● As a result the payload system underwent freefall from apogee 16
Payload Securement Flight Results Failure Solution Load-bearing ALC-powering servo bit snapped Implement a passive, bearing-based ALC system that is bolted to coupler The shear pins holding the payload broke and the Implement stronger shear pins payload was lost during decoupling Rover hook to sled was loose Modify design for a tighter fit of “lock key” piece 3D-printed PLA end piece holding sled snapped Redesign new sled system using metal or wood to prevent snapping 17
Requirements Verification Summary (Payload) - A large number of the payload requirements have not yet been completed . This is due to the loss of the payload during the first full scale launch and the necessary redesigns that came with that. However, it is foreseeable to have all possible requirements completed before the Payload Test Flight deadline of March 25th. - Radio telemetry has been completed - Basic drive system has been completed - Scoop actuation is in progress/nearly completed 18
Interfaces with Ground Systems - The vehicle utilizes the normal motor ignition method and is built to accept the ignitor. - The payload features an onboard radio that is linked to a ground receiver handled by one of our team members. Upon receiving the proper instructions, the team member will activate the payload bay through the transmitter, activating black powder charges and setting rover on its way. - Radio operates at frequency of 900MHz and has been verified for short distances 19
ADAS Initial Flight Results ● The initial flight proved that the ADAS system was structurally unreliable Components became undone resulting in ● a failure to deploy ● 3 main sources of failure: a. Constant beaglebone issues b. Motor driver shortage c. Loose pin connections 20
ADAS Hardware Changes The new ADAS system has ● modularized components to alleviate single points of failure and make it simpler to swap out and replace parts These hardware changes do not ● change the physical characteristics/energy of the vehicle apart from minor mass changes and deployment profile 21
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